In the laying of a flooring, as in the case of a wall coating, it is necessary for the substrate on which the flooring or wall coating is laid to be as flat as possible. It is moreover advantageous for the coating—whether this be in the form of a carpet, parquet, marble or ceramic tiles, or any other type of material—to be isolated from the substrate, the aim being to prevent any infiltration of moisture from the substrate itself, which could damage the coating, as well as to obtain a heat-insulating effect, i.e., reducing any heat losses.
In order to meet the needs outlined above, there have been available on the market for some time now flexible sheets made of synthetic material—referred to as stabilizing sheets—which are used as base for the laying of the coating. Said sheets are principally used for stabilizing floorings, i.e., they are set between the substrate to be coated and the final coating.
One of such stabilizing sheets is marketed by the present applicant under the commercial name EVERLAY and forms the subject of the Italian patent application No. 67797-A/85 in the name of the present applicant.
The sheet EVERLAY consists of a core layer of material made of silica-fibers (also commonly referred to as glass fibers) and two layers of plastic material applied on the opposite faces of the core layer.
This type of product, which has been used and marketed for some time now, has proved to be altogether satisfactory from the operative and functional points of view. It is, however, precisely the widespread use of this material that has shown that there is still further room for improvement; for example, as regards release into the environment of part of the silica fibers which make up the core layer (there being an increasing tendency to avoid this kind of phenomenon) and/or as regards other functional aspects and features of use.